The difference between oil-injected screw air compressor and oil-free

There are several main differences between oil-injected screw air compressors and oil-free screw air compressors:

lubrication method: The oil-injected screw compressor needs to lubricate the screw continuously during operation, so the lubricating oil and filter element need to be replaced regularly. The oil-free screw compressor uses a non-lubricating method and does not require any additional lubricating oil.

Maintenance cost: Since the oil-injected screw compressor needs to replace the lubricating oil and filter element regularly, its maintenance cost is relatively high. On the contrary, the maintenance cost of an oil-free screw compressor is lower because it does not require additional lubricating oil.

Working principle: The oil-injected screw compressor compresses the air through the high-speed rotating screw, and injects lubricating oil into the screw gap through the fuel injection pump to reduce friction and protect the screw surface from corrosion. The oil-free screw compressor uses the high-speed rotation of the two screws to compress and discharge the air without adding additional lubricating oil.

Flexibility of use: Since there is no need to add additional lubricating oil, the use of oil-free screw compressors in various occasions is more flexible.

Energy efficiency: Due to the use of oil injection lubrication, the energy efficiency of the oil-injected screw compressor may be higher than that of the oil-free screw compressor, because the lubricating oil can form an oil film between the rotors, which has the effects of lubrication and cooling, and can increase air tightness., Improve the volumetric efficiency of the air compressor.

In general, oil-injected screw air compressors and oil-free screw air compressors have their own characteristics and advantages. The choice of which type of air compressor depends on the specific application requirements and environmental conditions. For example, in the case of high gas purity requirements, such as food, pharmaceutical and other industries, oil-free screw compressors may be more suitable; and in some of the higher energy efficiency requirements, oil-injected screw compressors may be more advantages.